JP2018144779A - Hybrid vehicle and method for controlling hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel efficiency of a hybrid vehicle that includes an engine and a motor.SOLUTION: In a hybrid vehicle 100, when a request output Pr is lower than a threshold P1, an integrated controller 50 releases a first clutch 3 and drives a motor generator 4 at an optimum efficiency, and, when the request output Pr is higher than or equal to the threshold P1, couples the first clutch 3 to drive an engine 1 at an optimum efficiency.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hybrid vehicle and a hybrid vehicle control method.

  Patent Literature 1 describes an electric vehicle including a power generation module including an engine and a generator driven by the engine. In this electric vehicle, a traveling motor is driven by electric power generated by a generator.

JP-A-11-341606

  In the electric vehicle of Patent Document 1, the engine is used only for power generation. For this reason, even when the required driving force is high and the vehicle travels with better fuel efficiency, the motor is used as the drive source.

  Moreover, in the electric vehicle of patent document 1, when driving | running | working with a motor, the rotational speed of a motor will be decided by vehicle speed. For this reason, the motor cannot always be driven at the rotation speed of the optimum efficiency, and the fuel efficiency is deteriorated accordingly.

  The present invention has been made in view of such a technical problem, and an object thereof is to improve fuel efficiency in a hybrid vehicle including an engine and a motor.

  A hybrid vehicle according to an aspect of the present invention is charged by an engine, a continuously variable transmission provided in a power transmission path connecting the engine and driving wheels, a first motor driven by the engine and generating electric power, and the first motor. And a second motor that is provided between the continuously variable transmission and the engine in the power transmission path and that drives the driving wheels by the electric energy generated by the first motor or the electric energy supplied from the battery, The first clutch provided between the engine and the second motor in the power transmission path, and when the required output is less than the first predetermined value, the first clutch is released and the second motor is driven with optimum efficiency. And a controller that engages the first clutch and drives the engine with optimum efficiency when the required output is equal to or greater than the first predetermined value.

  The hybrid vehicle control method according to another aspect of the present invention includes an engine, a continuously variable transmission provided in a power transmission path connecting the engine and driving wheels, a first motor driven by the engine and generating electric power, A drive battery is driven by electric energy generated by the first motor or supplied from the battery, which is provided between the battery charged by the motor and the continuously variable transmission and the engine in the power transmission path. When the required output is less than the first predetermined value, the control method of the hybrid vehicle includes two motors and a first clutch provided between the engine and the second motor in the power transmission path. The first clutch is released to drive the second motor with optimum efficiency. When the required output is equal to or higher than the first predetermined value, the first clutch is engaged. Te to drive the engine at optimum efficiency.

  According to these aspects, the fuel efficiency can be improved by driving the second motor and the engine with the optimum efficiency.

1 is a configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is an MG efficiency map concerning the embodiment of the present invention. It is an engine efficiency map concerning the embodiment of the present invention. It is a flowchart of the control which the integrated controller which concerns on embodiment of this invention performs. It is a flowchart of the control which the integrated controller which concerns on embodiment of this invention performs.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle (hereinafter simply referred to as “vehicle”) 100. The vehicle 100 includes an engine 1, a generator motor 2 as a first motor, a first clutch 3, a motor generator (hereinafter referred to as "MG") 4 as a second motor, a second clutch 5, and an engine. 1 and a continuously variable transmission (hereinafter referred to as “CVT”) 6 provided in a power transmission path (hereinafter simply referred to as “power transmission path”) connecting the drive wheel 7 and an integrated controller 50 as a control unit. And comprising.

  The engine 1 is an internal combustion engine that uses gasoline, light oil, or the like as fuel, and the rotational speed, torque, and the like are controlled based on a command from the integrated controller 50.

  The generator motor 2 is driven by the engine 1 to generate power. The electric energy generated by the generator motor 2 is stored in the battery 9 via the inverter 8.

  MG4 is provided between CVT 6 and engine 1 in the power transmission path. MG4 is a synchronous rotating electrical machine in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The MG 4 is controlled by applying a three-phase alternating current generated by the inverter 8 based on a command from the integrated controller 50. The MG 4 can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 9. Further, when the rotor receives rotational energy from the drive wheel 7, the MG 4 functions as a generator that generates electrical energy at both ends of the stator coil, and can charge the battery 9.

  The first clutch 3 is a normally open hydraulic clutch that is interposed between the engine 1 and the MG 4 in the power transmission path. The engagement / release state of the first clutch 3 is controlled by the hydraulic pressure adjusted by the hydraulic control valve unit 71 based on a command from the integrated controller 50. The hydraulic control valve unit 71 is supplied with a discharge pressure of an oil pump (not shown) as a source pressure. For example, a dry multi-plate clutch is used as the first clutch 3.

  Second clutch 5 is provided between MG4 and CVT6 in the power transmission path. Engagement / release of the second clutch 5 is controlled by the hydraulic pressure adjusted by the hydraulic control valve unit 71 based on a command from the integrated controller 50. As the second clutch 5, for example, a normally open wet multi-plate clutch is used.

  The CVT 6 is disposed downstream of the MG 4 in the power transmission path, and can change the speed ratio steplessly according to the vehicle speed, the accelerator opening, and the like. The CVT 6 includes a primary pulley, a secondary pulley, and a belt stretched over both pulleys. A primary pulley pressure and a secondary pulley pressure are generated by a hydraulic control valve unit 71 using a discharge pressure from an oil pump (not shown) as a source pressure, and the movable pulley of the primary pulley and the movable pulley of the secondary pulley are moved in the axial direction by the pulley pressure, and the belt The gear ratio is changed steplessly by changing the pulley contact radius.

  A differential 12 is connected to the output shaft of the CVT 6 via a final reduction gear mechanism (not shown). Drive wheels 7 are connected to the differential 12 via a drive shaft 13.

  The integrated controller 50 includes a microcomputer that includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The integrated controller 50 can also be composed of a plurality of microcomputers.

  The integrated controller 50 includes a rotation speed sensor 51 that detects the rotation speed Ne of the engine 1, a rotation speed sensor 52 that detects the output rotation speed Nout of the second clutch 5 (= the input rotation speed of the CVT 6), and an accelerator opening degree. The accelerator position sensor 53, the CVT 6 select position (select lever or select switch for switching forward, reverse, neutral and parking), the vehicle switch 55 for detecting the vehicle speed, the remaining capacity of the battery 9 A signal from the SOC sensor 56 or the like to be detected is input. The integrated controller 50 performs various controls on the engine 1, the MG 4 (inverter 8), and the CVT 6 based on these input signals. The rotation speed Nm of MG4 can be obtained from the frequency of the inverter 8 by calculation.

  The integrated controller 50 drives the MG 4 based on the electric power from the battery 9 as the operation mode of the vehicle 100, and travels with the driving force of the MG 4 alone and the engine traveling mode with the driving force of the engine 1 alone. And a series travel mode in which the MG 4 is driven based on the electric power generated by the generator motor 2 and travels using only the driving force of the MG 4, and an assist travel mode in which the travel is performed using the driving force of the engine 1 and the driving force of the MG 4. Switch.

  In the motor travel mode, the vehicle 100 travels by driving only the MG 4 with electric power from the battery 9 with the first clutch 3 released and the second clutch 5 engaged. The motor travel mode is selected when the required output Pr of the vehicle 100 is low and the remaining capacity of the battery 9 is sufficient.

  In the engine travel mode, the vehicle 100 travels by driving only the engine 1 with the first clutch 3 and the second clutch 5 engaged. The engine travel mode is selected when the required output Pr of the vehicle 100 is relatively high.

  In the series travel mode, the vehicle 100 travels by driving only the MG 4 with the first clutch 3 released and the second clutch 5 engaged. In the series travel mode, the generator 1 is driven by the engine 1 to generate power, and the MG 4 is driven by the generated power. The series travel mode is selected when the required output Pr of the vehicle 100 is low and the remaining capacity of the battery 9 is low.

  In the assist travel mode, the vehicle 100 travels by driving the engine 1 and the MG 4 with the first clutch 3 and the second clutch 5 engaged. The assist travel mode is selected when the required output Pr of the vehicle 100 is high, specifically, when the required output Pr of the vehicle 100 cannot be compensated only by the output from the engine 1.

  Next, with reference to FIG. 2, control of the driving force of the MG 4 in the motor travel mode will be described.

  FIG. 2 is an MG efficiency map showing the relationship among the rotational speed Nm, torque Tm, and MG efficiency of MG4. Curves Lm1 to Lm5 in FIG. 2 are iso-output lines showing the relationship between the rotational speed Nm and the torque Tm at a certain output value of MG4. In this embodiment, the fuel efficiency of the MG 4 increases as the operating point moves toward the inside of the contour line (thin solid line). Further, the thick solid line (optimum efficiency line Mm) in FIG. 2 is a line connecting the optimum efficiency points at which the fuel efficiency at the respective rotational speeds of MG4 is highest. In FIG. 2, the iso-output lines are illustrated as Lm1 to Lm5, but actually, the characteristics do not change step by step, but the characteristics change continuously between the curves Lm1 to Lm5. Of course, the characteristics may be changed step by step.

  Based on the required output Pr of the vehicle 100, the integrated controller 50 calculates the target rotational speed Ntm and the target torque Ttm of the MG 4 corresponding to the required output Pr from the map shown in FIG. This will be specifically described below.

  Based on the accelerator opening detected by the accelerator opening sensor 53 and the vehicle speed detected by the vehicle speed sensor 55, the integrated controller 50 obtains an output (requested output Pr) output by the MG4.

  The integrated controller 50 obtains the intersection of the equal output line Lm and the optimum efficiency line Mm corresponding to the required output Pr obtained as described above from the MG efficiency map shown in FIG. Then, the integrated controller 50 drives the MG 4 with the rotation speed Nm and the torque Tm at the obtained intersection as the target rotation speed Ntm and the target torque Ttm of the MG 4. At this time, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotational speed Ntm and the vehicle speed. Specifically, the gear ratio of the CVT 6 is controlled so that a desired vehicle speed is obtained when the MG 4 is driven at the target rotational speed Ntm. As described above, in the motor travel mode of the present embodiment, by controlling the transmission ratio of the CVT 6 according to the target rotational speed Ntm and the vehicle speed, the MG 4 can always be driven with optimum efficiency and the vehicle 100 can travel.

  Next, with reference to FIG. 3, control of the driving force of the engine 1 in the engine travel mode will be described.

  FIG. 3 is an engine efficiency map showing the relationship between the rotational speed Ne, torque Te, and engine efficiency of the engine 1. Curves Le1 to Le5 in FIG. 3 are equal output lines showing the relationship between the rotational speed Ne and the torque Te at a certain output value of the engine 1, respectively. In the present embodiment, the fuel efficiency of the engine 1 increases as the operating point moves toward the inside (upper right in FIG. 3) of the contour line (thin solid line). Further, a thick solid line (optimum efficiency line Me) in FIG. 3 is a line connecting optimum efficiency points at which the fuel efficiency at the respective rotational speeds of the engine 1 is highest. In FIG. 3, the iso-output lines are illustrated as Le1 to Le5. However, in practice, the characteristics do not change stepwise, but the characteristics change continuously between the curves Le1 to Le5. Of course, the characteristics may be changed step by step.

  The integrated controller 50 calculates the target rotational speed Nte and the target torque Tte of the engine 1 corresponding to the required output Pr from the map shown in FIG. 3 based on the required output Pr of the vehicle 100. This will be specifically described below.

  The integrated controller 50 obtains an output output from the engine 1 based on the accelerator opening detected by the accelerator opening sensor 53 and the vehicle speed detected by the vehicle speed sensor 55. Further, the integrated controller 50 obtains a required power generation amount for charging the battery 9 based on an output signal from the SOC sensor 56 that detects the remaining capacity of the battery 9. Then, the integrated controller 50 obtains a required output Pr for the engine 1 based on an output for driving auxiliary machines (not shown) and an output for satisfying the required power generation amount.

  The integrated controller 50 obtains the intersection of the equal output line Le and the optimum efficiency line Me corresponding to the required output Pr obtained as described above in the engine efficiency map shown in FIG. Then, the integrated controller 50 drives the engine 1 with the rotation speed Ne and the torque Te at the obtained intersection as the target rotation speed Nte and the target torque Tte of the engine 1. At this time, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotation speed Nte and the vehicle speed. Specifically, the gear ratio of CVT 6 is controlled so that the desired vehicle speed is obtained when engine 1 is driven at target rotational speed Nte. As described above, in the engine travel mode of the present embodiment, the engine 100 is always driven at the optimum efficiency to travel the vehicle 100 by controlling the transmission ratio of the CVT 6 according to the target rotational speed Nte and the vehicle speed.

  Next, control of the driving force of the engine 1 and the MG 4 in the series travel mode will be described.

  When the capacity necessary for MG 4 to drive vehicle 100 for a certain period of time does not remain in battery 9, the series travel mode is selected. When the series travel mode is selected, the integrated controller 50 drives the engine 1 by driving the engine 1. At this time, the integrated controller 50 drives the power generation motor 2 (engine 1) so that the power generation amount satisfies the power for driving the vehicle 100 and the power for charging the battery 9 by the MG 4. In the series travel mode, since the first clutch 3 is released, the output of the engine 1 is not used as a driving force for causing the vehicle 100 to travel, and the power generation by the power generation motor 2 (driving the MG 4 and the battery 9) Used for charging).

  The integrated controller 50 obtains a required power generation amount for charging the battery 9 based on an output signal from the SOC sensor 56 that detects the remaining capacity of the battery 9. Based on the output for driving the auxiliary machines (not shown), the output for satisfying the required power generation amount, and the output necessary for the MG 4 to output the required output Pr, the request for the engine 1 is finally obtained. The output Pre is obtained. Then, the integrated controller 50 obtains the intersection point between the optimum efficiency line Me of the engine 1 and the equal output line Le corresponding to the required output Pre in FIG. The integrated controller 50 drives the engine 1 with the rotational speed Ne and torque Te at the obtained intersection as the target rotational speed Nte and target torque Tte of the engine 1.

  Further, the integrated controller 50 controls the driving force of the MG 4 based on the request output Pr. Since the control of the driving force of MG4 is the same as in the motor travel mode, the description thereof is omitted.

  As described above, in the series travel mode of the present embodiment, as in the motor travel mode, by controlling the transmission ratio of the CVT 6 in accordance with the target rotational speed Ntm and the vehicle speed, the MG 4 is always driven at the optimum efficiency and the vehicle. 100 can be run. In addition, the engine 1 is driven at an optimum efficiency to generate the amount of power generated by the generator motor 2. As a result, the engine 1 can be driven with optimum efficiency to charge the battery 9 and supply power to the MG 4.

  Next, control of the driving force of the engine 1 and the MG 4 in the assist travel mode will be described.

  When the required output Pr of the vehicle 100 cannot be compensated only by the output from the engine 1, the assist travel mode is selected. When the assist travel mode is selected, the integrated controller 50 controls the MG 4 to output the difference between the requested output Pr and the output from the engine 1. Specifically, the integrated controller 50 calculates the sum of outputs when the engine 1 and the MG 4 are driven at the same rotational speed on the optimum efficiency line Me of the map shown in FIG. 3 and the optimum efficiency line Mm of the map shown in FIG. The target rotational speed Nte (= Ntm) and the target torques Tte and Ttm so as to obtain the required output Pr are obtained. Then, the integrated controller 50 is configured so that the sum of outputs when the engine 1 and the MG 4 are driven at the same target rotational speed Nte (= Ntm) and the respective target torques Tte and Ttm becomes the required output Pr. Engine 1 and MG4 are driven. Further, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotational speed Nte (= Ntm) and the vehicle speed. As described above, in the assist travel mode of the present embodiment, the required output is achieved while driving the engine 1 and the MG 4 with optimum efficiency by controlling the transmission ratio of the CVT 6 according to the target rotational speed Nte (= Ntm) and the vehicle speed. The vehicle 100 can be driven while satisfying Pr. When the MG 4 has a speed change mechanism, the final rotation speed is controlled to be the same as the target rotation speed Nte of the engine 1.

  Next, switching of the operation mode of the vehicle 100 executed by the integrated controller 50 will be described with reference to the flowcharts shown in FIGS. 4 and 5.

  In step S11, it is determined whether the required output Pr is less than the threshold value P1. Specifically, in step S11, it is determined whether or not the request output Pr can be output only by MG4. The threshold value P1 can be set so that the required output Pr can be output only by MG4, and the fuel efficiency is better when the engine 1 is driven at the optimum efficiency than when the engine 1 is driven at the optimum efficiency. If the request output Pr is less than the threshold value P1, that is, if the request output Pr can be output only by MG4, the process proceeds to step S12, and if the request output Pr is greater than or equal to the threshold value P1, that is, the request output Pr is set to MG4. If it cannot be output only, the process proceeds to step S22 (see FIG. 5).

  In step S12, it is determined whether the remaining capacity of the battery 9 is equal to or greater than the threshold value E1. Specifically, the integrated controller 50 determines whether the remaining capacity of the battery 9 is equal to or greater than a threshold value E1 (first predetermined amount) based on an output signal from the SOC sensor 56. The threshold E1 is set to a remaining capacity necessary for the MG 4 to drive the vehicle 100 for a certain period of time. If the remaining capacity of the battery 9 is equal to or greater than the threshold E1, the process proceeds to step S13, and if the remaining capacity of the battery 9 is less than the threshold E1, the process proceeds to step S17.

  In step S13, the first clutch 3 is turned off and the second clutch 5 is turned on. Specifically, the first clutch 3 is released and the second clutch 5 is engaged by the hydraulic pressure adjusted by the hydraulic control valve unit 71. Thereby, the power transmission path from engine 1 is cut off and only the power transmission path from MG4 is connected, so vehicle 100 travels only by the output from MG4.

  In step S14, MG4 is driven with optimum efficiency. Specifically, the integrated controller 50 obtains the target rotational speed Ntm and the target torque Ttm of MG4 from the MG efficiency map shown in FIG. 2 as described above, so that MG4 becomes the target rotational speed Ntm and the target torque Ttm. To drive.

  In step S15, the CVT 6 is shifted. Specifically, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotation speed Ntm and the vehicle speed.

  In step S16, it is determined whether or not the accelerator opening change amount is less than a threshold value α. Specifically, it is determined whether the change amount of the accelerator opening detected by the accelerator opening sensor 53 is less than the threshold value α. If the accelerator opening change amount is less than the threshold value α, the state is maintained as it is. If the accelerator opening change amount is equal to or greater than the threshold value α, the required output Pr of the vehicle 100 has changed, and the process returns to step S11.

  As described above, when the required output Pr is less than the threshold value P1 and the remaining capacity of the battery 9 is equal to or greater than the threshold value E1, the integrated controller 50 selects a motor travel mode that is driven only by MG4. In the motor travel mode, the MG 4 is driven at the optimum efficiency by controlling the CVT 6 so that the vehicle 100 travels, so that the fuel efficiency can be improved.

  Next, the case where it is determined in step S12 that the remaining capacity of the battery 9 is less than the threshold value E1 will be described. As described above, when it is determined in step S12 that the remaining capacity of the battery 9 is less than the threshold value E1, the process proceeds to step S17.

  In step S17, the first clutch 3 is turned off and the second clutch 5 is turned on. Specifically, the first clutch 3 is released and the second clutch 5 is engaged by the hydraulic pressure adjusted by the hydraulic control valve unit 71. Thereby, the power transmission path from engine 1 is cut off and only the power transmission path from MG4 is connected, so vehicle 100 travels only by the output from MG4.

  In step S18, the engine 1 is driven with optimum efficiency. More specifically, in this state, the battery 9 does not have a capacity necessary for the MG 4 to drive the vehicle 100 for a certain period of time. For this reason, the integrated controller 50 drives the generator 1 by driving the engine 1 (step S19). The generator motor 2 is driven so as to have a power generation amount that satisfies the power for driving the vehicle 100 and the power for charging the battery 9 by the MG 4 as described above. At this time, since the first clutch 3 is released, the output of the engine 1 is not used as a driving force for driving the vehicle 100 but is used for driving the MG 4 and charging the battery 9.

  Then, the integrated controller 50 obtains the target rotational speed Nte and the target torque Tte of the engine 1 from the engine efficiency map shown in FIG. 3 as described above, so that the engine 1 becomes the target rotational speed Nte and the target torque Tte. To drive.

  In step S20, MG4 is driven with optimum efficiency. Specifically, the integrated controller 50 obtains the target rotational speed Ntm and the target torque Ttm of MG4 from the MG efficiency map shown in FIG. 2 as described above, so that MG4 becomes the target rotational speed Ntm and the target torque Ttm. To drive.

  In step S21, the CVT 6 is shifted. Specifically, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotation speed Ntm and the vehicle speed. Since step S16 is as described above, description thereof is omitted.

  Thus, when the required output Pr is less than the threshold value P1 and the remaining capacity of the battery 9 is less than the threshold value E1, the integrated controller 50 drives the generator motor 2 with the engine 1 to generate power, The series travel mode for charging the battery 9 is selected while driving the MG 4 with the generated power. In the series travel mode, the engine 1 is driven with the optimum efficiency and the electric motor 2 generates electric power, and the MG 4 can be driven with the optimum efficiency by controlling the CVT 6 so that the vehicle 100 can travel, thereby improving the fuel efficiency. can do.

  Next, the case where it is determined in step S11 that the required output Pr is equal to or greater than the threshold value P1 will be described. As described above, when it is determined in step S11 that the required output Pr is equal to or greater than the threshold value P1, the process proceeds to step S22.

  In step S22, it is determined whether the required output Pr is less than the threshold value P2. Specifically, in step S22, it is determined whether or not the request output Pr can be output only by the engine 1. The threshold value P2 is larger than the threshold value P1, and more specifically, driving the engine 1 at the optimum efficiency is more fuel efficient than driving the MG 4 at the optimum efficiency, and the engine 1 can output only. It is set below the correct value. As a result, if the requested output Pr is less than the threshold value P2, that is, if the requested output Pr can be output only by the engine 1, the process proceeds to step S23, and if the requested output Pr is greater than or equal to the threshold value P2, that is, the request If the output Pr cannot be output only by the engine 1, the process proceeds to step S26.

  In step S23, the first clutch 3 and the second clutch 5 are turned on. Specifically, the first clutch 3 and the second clutch 5 are engaged by the hydraulic pressure adjusted by the hydraulic control valve unit 71. Thereby, the power transmission path from the engine 1 is connected, and the vehicle 100 travels by the output from the engine 1.

  In step S24, the engine 1 is driven with optimum efficiency. Specifically, the integrated controller 50 obtains the target rotational speed Nte and the target torque Tte of the engine 1 from the engine efficiency map shown in FIG. 3 as described above, and determines the engine 1 as the target rotational speed Nte and the target torque Tte. Drive to be.

  In step S25, the CVT 6 is shifted. Specifically, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotation speed Nte and the vehicle speed. Since step S16 is as described above, description thereof is omitted.

  Thus, when the required output Pr is equal to or greater than the threshold value P1 and less than the threshold value P2, the integrated controller 50 selects an engine travel mode that is driven only by the engine 1. In the engine travel mode, by controlling the CVT 6, the engine 1 can be driven at the optimum efficiency and the vehicle 100 can travel, so that the fuel efficiency can be improved.

  If the remaining capacity of the battery 9 is insufficient during the engine running mode, the engine 1 drives the generator motor 2 to charge the battery 9. In this case, the required output Pr is a value to which an output for satisfying the required power generation amount of the battery 9 is added.

  Next, the case where it is determined in step S22 that the required output Pr is equal to or greater than the threshold value P2 will be described. As described above, when it is determined in step S22 that the required output Pr is greater than or equal to the threshold value P2, the process proceeds to step S26.

  In step S26, it is determined whether the remaining capacity of the battery 9 is greater than or equal to a threshold value E2. Specifically, the integrated controller 50 determines whether the remaining capacity of the battery 9 is equal to or greater than a threshold value E2 (second predetermined amount) based on an output signal from the SOC sensor 56. The threshold E2 is set to a remaining capacity necessary for the MG 4 to perform assist driving for a certain period of time. If the remaining capacity of the battery 9 is greater than or equal to the threshold E2, the process proceeds to step S27, and if the remaining capacity of the battery 9 is less than the threshold E2, the process proceeds to step S23. Since the flow after step S23 is as described above, the description thereof is omitted.

  In step S27, the first clutch 3 and the second clutch 5 are turned on. Specifically, the first clutch 3 and the second clutch 5 are engaged by the hydraulic pressure adjusted by the hydraulic control valve unit 71. Thereby, the power transmission path from engine 1 and MG4 is connected, and vehicle 100 travels by the output from engine 1 and MG4.

  In step S28, the engine 1 is driven with optimum efficiency, and in step S29, MG4 is driven with optimum efficiency. Specifically, in steps S28 and S29, as described above, the integrated controller 50 determines whether the engine 1 and MG4 are in the optimum efficiency line Mm of the map shown in FIG. 2 and the optimum efficiency line Me of the map shown in FIG. A target rotational speed Nte (= Ntm) and target torques Tte and Ttm are obtained so that the sum of outputs when driving at the same rotational speed becomes the required output Pr. Then, the integrated controller 50 is configured so that the sum of outputs when the engine 1 and the MG 4 are driven at the same target rotational speed Nte (= Ntm) and the respective target torques Tte and Ttm becomes the required output Pr. Engine 1 and MG4 are driven.

  In step S30, the CVT 6 is shifted. Specifically, the integrated controller 50 controls the gear ratio of the CVT 6 based on the target rotational speed Nte (= Ntm) and the vehicle speed. Since step S16 is as described above, description thereof is omitted.

  As described above, the integrated controller 50 assists the output of the engine 1 with the output of the MG 4 when the required output Pr is equal to or greater than the threshold value P2 and the remaining capacity of the battery 9 is equal to or greater than the threshold value E2. Select a mode. That is, when the required output Pr cannot be covered only by the output of the engine 1 and the remaining capacity of the battery 9 is sufficient to drive the MG 4, the integrated controller 50 is driven by the engine 1 and MG 4. Select the assist driving mode to be used. In the assist travel mode, the engine 1 and the MG 4 can be driven at the optimum efficiency by controlling the CVT 6 so that the vehicle 100 can travel, so that the fuel efficiency can be improved.

  As described above, according to the vehicle 100 including the integrated controller 50, the MG 4 is driven based on the electric power from the battery 9, and the motor travel mode in which the MG 4 is driven by the driving force of only the MG 4 and the driving force of only the engine 1 is used. Engine traveling mode for traveling, series traveling mode for driving the MG 4 based on the electric power generated by the generator motor 2 and traveling by the driving force of the MG 4 alone, assist traveling mode for traveling by the driving force of the engine 1 and the driving force of the MG 4 In any case, by controlling the transmission ratio of the CVT 6, the engine 1 and the MG 4 can be driven with optimum efficiency, and the vehicle 100 can be driven. Thereby, the fuel efficiency of the vehicle 100 can be improved.

  According to the above embodiment, there exist the following effects.

  In the vehicle 100, when the required output Pr is less than the threshold value P1 (first predetermined value), the integrated controller 50 (control unit) releases the first clutch 3 and drives the MG 4 (second motor) with optimum efficiency. When the required output Pr is equal to or greater than the threshold value P1 (first predetermined value), the first clutch 3 is engaged and the engine 1 is driven with optimum efficiency.

  In this configuration, when the vehicle 100 is driven by either the MG 4 (second motor) or the engine 1, the MG 4 (second motor) and the engine 1 are each driven with optimum efficiency. Therefore, fuel efficiency can be improved (effect corresponding to claims 1 and 6).

  When the required output Pr is less than the threshold value P1 (first predetermined value) and the remaining capacity of the battery 9 is less than the threshold value E1 (first predetermined amount), the integrated controller 50 drives the engine 1 with optimum efficiency. The power generation motor 2 (first motor) generates electric power, and the electric power (electric energy) generated by the power generation motor 2 (first motor) drives the MG 4 (second motor).

  In this configuration, even when the remaining capacity of the battery 9 is insufficient, the MG 4 (second motor) can be driven by the electric power (electric energy) generated by the power generation motor 2 (first motor). Furthermore, the vehicle 100 can be driven by driving the engine 1 and the MG 4 (second motor) with optimum efficiency. Therefore, fuel efficiency can be improved (effect corresponding to claim 2).

  When the required output Pr is equal to or greater than a threshold value P2 (second predetermined value) that is greater than the threshold value P1 (first predetermined value), the integrated controller 50 executes assist travel by MG4 (second motor).

  According to this configuration, when the output of the engine 1 is insufficient, it is assisted by the MG 4 (second motor), so that it is possible to avoid insufficient output even if the engine 1 is downsized (corresponding to claim 3). effect).

  The integrated controller 50 uses the MG4 (second motor) when the required output Pr is equal to or greater than the threshold value P2 (second predetermined value) and the remaining capacity of the battery 9 is less than the threshold value E2 (second predetermined amount). Assist travel (assist travel mode) is not executed.

  According to this configuration, since a certain remaining capacity of the battery 9 can be ensured, the operation of an auxiliary machine (not shown) driven by the electric power from the battery 9 is not hindered (effect corresponding to claim 4).

  Vehicle 100 further includes a second clutch 5 between MG4 (second motor) and CVT6 (continuously variable transmission).

  According to this configuration, by releasing the second clutch 5, regeneration of rotational energy from the drive wheels 7 by the MG 4 can be interrupted. Thus, it is possible to prevent the vehicle speed from being lowered when the vehicle 100 is traveling inertia (effect corresponding to claim 5).

  The embodiment of the present invention has been described above, but the above embodiment is merely a part of an application example of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  For example, in the vehicle 100, the second clutch 5 may not be provided if it is not necessary. Moreover, you may use the motor which does not have a regeneration function as a 2nd motor.

100 vehicles (hybrid vehicles)
1 Engine 2 Generator motor (first motor)
3 First clutch 4 Motor generator (second motor)
5 Second clutch 6 CVT (continuously variable transmission)
7 Driving wheel 9 Battery 50 Integrated controller (control unit)
56 SOC sensor

Claims (6)

Engine,
A continuously variable transmission provided in a power transmission path connecting the engine and driving wheels;
A first motor driven by the engine to generate electricity;
A battery charged by the first motor;
A second motor that is provided between the continuously variable transmission and the engine in the power transmission path, and that drives the driving wheels by electric energy generated by the first motor or electric energy supplied from the battery. When,
A first clutch provided between the engine and the second motor in the power transmission path;
When the required output is less than the first predetermined value, the first clutch is released to drive the second motor with optimum efficiency, and when the required output is greater than the first predetermined value, the first A control unit that engages one clutch and drives the engine with optimum efficiency;
A hybrid vehicle comprising: The hybrid vehicle according to claim 1,
When the required output is less than the first predetermined value and the remaining capacity of the battery is less than a first predetermined amount, the control unit drives the engine with optimum efficiency to drive the first motor. And a second vehicle driven by the electric energy generated by the first motor. A hybrid vehicle according to claim 1 or 2,
The hybrid vehicle according to claim 1, wherein the controller executes assist traveling by the second motor when the requested output is equal to or greater than a second predetermined value that is greater than the first predetermined value. The hybrid vehicle according to claim 3,
The control unit does not execute assist travel by the second motor when the requested output is equal to or greater than the second predetermined value and the remaining capacity of the battery is less than a second predetermined amount. A featured hybrid vehicle. A hybrid vehicle according to any one of claims 1 to 4,
The hybrid vehicle further comprising a second clutch between the second motor and the continuously variable transmission. Engine,
A continuously variable transmission provided in a power transmission path connecting the engine and driving wheels;
A first motor driven by the engine to generate electricity;
A battery charged by the first motor;
A second motor that is provided between the continuously variable transmission and the engine in the power transmission path, and that drives the driving wheels by electric energy generated by the first motor or electric energy supplied from the battery. When,
A control method for a hybrid vehicle, comprising: a first clutch provided between the engine and the second motor in the power transmission path,
When the required output is less than the first predetermined value, the first clutch is released to drive the second motor with optimum efficiency, and when the required output is greater than the first predetermined value, the first A control method for a hybrid vehicle, wherein one clutch is engaged and the engine is driven with optimum efficiency.

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